The invention pertains to a sputter cathode with an electrode to which at least one target to be sputtered is attached.
Sputter cathodes of the type indicated above are used in coating systems for sputtering and are generally known. Its target is usually bonded permanently to the electrode. This leads to problems, however, when the coefficient of expansion of the target material differs significantly from that of the electrode and when the electrode and the target have large surface areas. Widely differing coefficients of expansion occur, for example, when the target consists of indium-tin oxide and thus the metal electrode must be bonded to a nonmetal. Large-area electrodes and targets are required when it is desired to coat substrates with large surface areas in a static manner, that is, without the movement of the substrate.
To prevent the target from cracking as a result of a difference in the coefficients of expansion, sputter cathodes are known in which, instead of a single target with a large surface area, several targets are bonded to the electrode like tiles, one next to the other. The disadvantage here, however, is that the solder used for bonding also intrudes between the targets and is atomized during sputtering, with the result that the layer sputtered onto the substrate is contaminated.